Method for restructuration of raw meat for production of restructured raw meat by addition to the meat of transglutaminase

ABSTRACT

The method for restructuration of raw meat for production of restructured raw meat by addition to the meat of transglutaminase comprises the further addition of phosphate (optional) and sodium chloride, with a subsequent temperature treatment. Hereby the cohesion and hardness of the restructured raw meat is improved, and it can be sold as a refrigerated meat product.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT/DK94/00339 filed Sep. 13,1994, which is incorporated herein by reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT/DK94/00339 filed Sep. 13,1994, which is incorporated herein by reference.

The invention comprises a method for restructuration of raw meat forproduction of restructured raw meat by addition to the meat oftransglutaminase.

Methods of this kind are described in the literature. Reference can bemade to Trends in modern meat technology 2, Pudoc Wageningen 1988, pages125-129, from which it appears that meat pieces can be converted to acoherent meat mass by addition of i.a. transglutaminase. Reference alsocan be made to Japanese patent application No. JP 2079956 (WPI Acc. no.90-129641 in Dialog), from which it appears that moulded meat can beprepared by moulding waste pieces of meat with transglutaminase.

The critical factor in relation to the methods of the above indicatedkind is the texture parameters of the restructured raw meat, as measuredby texture profile analyses, especially the cohesion and the hardness.These texture parameters, especially the cohesion and the hardness areunsatisfactory and thus open to improvement.

EP 0201975 describes a method of the same kind as the method accordingto the invention. However, a must in relation to this prior art methodis the use of a binding material of external fibrin, which againnecessitates the use of fibrinogen and the expensive thrombin.

Thus, the purpose of the invention is the provision of a cheap methodfor restructuration of raw meat for production of restructured raw meat,in relation to which the texture parameters of the restructured rawmeat, especially the cohesion and the hardness, are improvedconsiderably in comparison to the prior art methods.

The method according to the invention for restructuration of raw meatfor production of restructured raw meat by addition to the meat oftransglutaminase is characterized by the fact that no external bindingprotein is added to the meat, and that besides transglutaminase also upto 0.4% by weight of a phosphate of an alkali metal and between 1.5 and4% by weight of sodium chloride, related to the weight of the meat, isadded to the meat and mixed into the meat, whereafter the thus generatedmeat mixture is exposed to a temperature between 5° C. and 37° C. in atime interval between 90 minutes and 48 hours. If the transglutaminaserequires calcium for activity, calcium should be added in a satisfactoryconcentration, as in prior art methods of this kind. Use of thetransglutaminase factor XIIIa is specially preferred in the invention.For best results the large time intervals should be used in relation tothe low temperatures, and vice versa.

Surprisingly it has been found that the texture parameters of therestructured raw meat prepared by means of the method according to theinvention, especially the cohesion and the hardness, exhibits asignificant improvement in comparison to the cohesion and the hardnessof the meat prepared by prior art methods.

It has been found that the meat prepared by means of the methodaccording to the invention can be sold as a refrigerated meat product,because the refrigerated meat product exhibits a superior cohesion andhardness, as compared to prior art restructured raw meat.

Transglutaminase is added to the meat in the usual amounts, i.e. between0.01 and 1% of pure transglutaminase protein, calculated in relation tothe substrate, i.e. the meat protein.

By phosphates in this invention we understand ortophosphates,pyrophosphates and polyphosphates, especially tripolyphosphates, ofalkali metals, especially sodium or potassium. Phosphates of alkalineearth metals, e.g. calcium phosphates, are not suited for the invention.

It has been found that addition of the phosphate of an alkali metal sabove 0.4% does not improve the cohesion and the hardness of the meat.Also, it has been found that addition of sodium chloride below 1.5% doesnot improve the cohesion and hardness of the meat; furthermore, anaddition of sodium chloride above 4% by weight would not be relevant forraw meat products.

A preferred embodiment of the method according to the invention ischaracterized by the fact that the phosphate of an alkali metal is addedin an amount of between 0.15 and 0.25% by weight. In this mannerexcellent improvements of the cohesion and hardness are obtained.

A preferred embodiment of the method according to the invention ischaracterized by the fact that the sodium chloride is added in an amountof between 2 and 3% by weight. In this manner excellent improvements ofthe cohesion and hardness are obtained.

A preferred embodiment of the method according to the invention, ischaracterized by the fact that the phosphate (if added), thetransglutaminase, and the sodium chloride is added as an aqueoussolution. This solution should preferably be as concentrated aspossible. In this manner the subsequent mixing process is carried outwithout any difficulty.

From U.S. Pat. No. 4,917,904 it appears that the properties of meat canbe modified by addition of transglutaminase, salt and a phosphate. Thisprior art, however, does not describe the use of an alkali metalphosphate, and furthermore, this prior art method is not a method forproduction of restructured raw meat, but a method for production of hightemperature treated, smoked meat. Thus, this prior art method differssignificantly from the method according to the invention.

EXAMPLE

50 g of meat minced twice in a Braun mincing machine (for kitchen use)with holes 4.5 mm in diameter, 4.7 ml distilled water, in which thelater specified additives (a g of sodium chloride and b g of sodiumtripolyphosphate), except for transglutaminase, were dissolved,inclusive of 0.3 ml 1M calcium chloride corresponding to 5 mM, weremixed. An amount of F XIII a corresponding to 44 mg of pure F XIII aenzyme protein dissolved in 5 ml of distilled water and stirred for 30minutes was added to the meat and mixed well with the meat. The meatmixture was filled into polyethylene casings with a flattened crossmeasure of 45 mm and a length of 250 mm. These samples are referred toas sausages in the following.

The sausages were then placed in a water bath heated to 37° C. for 90minutes and then stored in a refrigerator at 5° C. until texture profileanalyses were performed the following day. All experiments were carriedout as two times replicates.

The texture profile analyses were carried out as follows.

An Instron machine, type 4301, was used to carry out the texture profileanalyses. The load cell used was 1000N, and the test stamp was 35 mm.The compression was 75% and the speed was 100 mm/minute. The load rangewas 10%, corresponding to 100N, and the paper speed compared to thecylinder speed was 10:1. The measurement was carried out on samples thatwere 10 mm thick and 29 mm in diameter, and the compression was carriedout twice on each piece. The temperature of the sample was 25° C. at thetime of the analysis. Five samples of each sausage were analysed.

According to Klettner, P-G (1989), Fleischwirtschaft, 69(2), 225 thefirst stress applied caused a breakdown of texture, expressed in thefirst peak, and then a second peak produced by the whole squeezingprocess. The height of the first peak is defined as the breakingstrength (B_(c)) and the second peak as the hardness (F_(c)). The csymbolizes the compression. After the first stress the test stamp liftedupwards before the second stress was applied. The ratio between surfacesunder the second stress (A₂) and the first stress (A₁) is the cohesion(C_(c)). This ratio was determined by cutting out the surfaces andweighing them.

The values for a and b and the corresponding values for cohesion andhardness, measured as defined above, were as follows, vide Table 1.

                  TABLE 1                                                         ______________________________________                                        Status     a     b          Cohesion                                                                             Hardness                                   ______________________________________                                        Prior art  0     0          0.36   37.48                                      Invention  1.2   0          0.36   53.22                                                 1.2   0.12       0.46   90.35                                                 1.8   0          0.41   73.64                                                 1.8   0.12       0.48   109.40                                     ______________________________________                                    

It appears from Table 1 that the values for cohesion and hardness in nocase is inferior for the invention in comparison to prior art, and thatthe values for cohesion and hardness as an average is much better forthe invention in comparison to prior art.

We claim:
 1. A method for restricting raw meat, comprising(a) adding tothe raw meat (i) a transglutaminase, (ii) sodium chloride in an amountin the range of 1.5-4% by weight, based on the the weight of the rawmeat and (iii) an alkali metal phosphate in the range of 0.15-0.25% byweight, based on the weight of the raw meat; (b) mixing thetransglutaminase, the sodium chloride and the phosphate with the rawmeat to form a meat mixture; and (c) exposing the meat mixture to atemperature in the range of 5°-37° C. for a period of time in the rangeof 90 minutes to 48 hours;wherein that no external binding protein isadded to the meat.
 2. The method according to claim 1, wherein thealkali metal phosphate is sodium tripolyphosphate.
 3. The methodaccording to claim 1, wherein the sodium chloride is added in an amountin the range of 2-3% by weight.
 4. The method according to claim 2,wherein the sodium chloride is added in an amount in the range of 2-3%by weight.
 5. The method according to claim 1, wherein thetransglutaminase, the sodium chloride and the phosphate are added in theform of an aqueous solution.
 6. The method according to claim 2, whereinthe transglutaminase, the sodium chloride and the phosphate are added inthe form of an aqueous solution.
 7. The method according to claim 3,wherein the transglutaminase, the sodium chloride and the phosphate areadded in the form of an aqueous solution.
 8. The method according toclaim 4, wherein the transglutaminase, the sodium chloride and thephosphate are added in the form of an aqueous solution.